Shape dummy cells that are designed to have the same dimensions and structures as MTJ memory cells are additionally provided in the peripheral portion of an MTJ memory cell array in which normal MTJ memory cells for storing data are arranged in a matrix. The MTJ memory cells and the shape dummy cells are sequentially arranged so as to have a uniform pitch throughout the entirety. Accordingly, non-uniformity between MTJ memory cells in the center portion and in border portions of the MTJ memory cell array, respectively, after manufacture due to high and low densities of the surrounding memory cells can be eliminated.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A thin film magnetic memory device comprising: a memory cell array in which a plurality of magnetic memory cells is sequentially arranged, each of said magnetic memory cells including a magnetic memory element having a plurality of magnetic layers at least one of which is magnetized in the direction in accordance with storage data; a plurality of shape dummy cells sequentially arranged with said plurality of magnetic memory cells in the outside of said memory cell array, each of said shape dummy cells including a dummy magnetic memory element designed to have the same structure and the same dimensions as said magnetic memory element; and wherein said memory cell array is divided into a plurality of memory blocks, and said plurality of shape dummy cells is sequentially arranged with said plurality of magnetic memory cells within each of said memory blocks around the periphery of each of said plurality of memory blocks.
2. A thin film magnetic memory device comprising: a memory cell array in which a plurality of magnetic memory cells is sequentially arranged, each of said magnetic memory cells including a magnetic memory element having a plurality of magnetic layers at least one of which is magnetized in the direction in accordance with storage data; a plurality of shape dummy cells sequentially arranged with said plurality of magnetic memory cells in the outside of said memory cell array, each of said shape dummy cells including a dummy magnetic memory element designed to have the same structure and the same dimensions as said magnetic memory element; and further comprising: a circuit element formed in the same planer region as of said dummy magnetic memory element and in a layer differing from that of said dummy magnetic memory element, in at least one of said plurality of shape dummy cells.
3. A thin film magnetic memory device comprising: a memory cell array in which a plurality of magnetic memory cells is sequentially arranged, each of said magnetic memory cells including a magnetic memory element having a plurality of magnetic layers at least one of which is magnetized in the direction in accordance with storage data; a plurality of shape dummy cells sequentially arranged with said plurality of magnetic memory cells in the outside of said memory cell array, each of said shave dummy cells including a dummy magnetic memory element designed to have the same structure and the same dimensions as said magnetic memory element; and wherein each of said memory cells further includes an access element formed in a layer differing from that of said magnetic memory element for controlling a current passing through said magnetic memory element at the time of data read, said thin film magnetic memory device further comprises a plurality of dummy shape elements sequentially arranged with said access element outside of said memory cell array, each of said shape dummy elements has the same structure and the same dimensions as of said access element, at least a part of said plurality of shape dummy cells is formed in the same planar region as of one of said plurality of dummy shape elements, and said dummy magnetic memory element and each of said dummy shape elements, respectively, are formed in different layers in said same planar region.
4. The thin film magnetic memory device according to claim 3 , wherein the number of said dummy magnetic memory elements arranged in the same direction and the number of said dummy shape elements arranged in the same direction are different from each other outside of said memory cell array.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
May 20, 2003
August 9, 2005
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